9.3.2.4 Commands

Reading of the Flash/EEPROM and writing of the page buffer is handled with normal load/store instructions. Other operations, such as writing and erasing the memory arrays, are handled by commands in the NVM.

To execute a command in the NVM:
  1. Confirm that any previous operation is completed by reading the Busy Flags (EEBUSY and FBUSY) in the NVMCTRL.STATUS register.
  2. Write the NVM command unlock to the Configuration Change Protection register in the CPU (CPU.CCP).
  3. Write the desired command value to the CMD bits in the Control A register (NVMCTRL.CTRLA) within the next four instructions.